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A372913
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Decimal expansion of (1/31)*(14*sqrt(5 - 2*sqrt(5)) + 4*sqrt(5 + 2*sqrt(5))).
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4
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7, 2, 5, 2, 3, 6, 4, 3, 6, 7, 9, 9, 2, 2, 7, 9, 3, 5, 8, 9, 7, 3, 4, 5, 0, 6, 1, 5, 7, 6, 6, 5, 4, 8, 9, 6, 4, 7, 2, 6, 4, 8, 4, 5, 4, 0, 5, 3, 6, 8, 0, 2, 6, 4, 0, 8, 5, 7, 2, 7, 5, 3, 4, 9, 7, 8, 7, 0, 7, 8, 9, 1, 6, 0, 7, 0, 9, 4, 4, 1, 6, 5, 0, 6, 6, 6
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OFFSET
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0,1
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LINKS
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FORMULA
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Equals Sum_{k>=0} tan(k*Pi/5)/2^k.
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EXAMPLE
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0.72523643679922793589734506157665489647264845405...
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MATHEMATICA
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s = Sum[Tan[k Pi/5]/2^k, {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d]]
N[1/31 (14 Sqrt[5 - 2 Sqrt[5]] + 4 Sqrt[5 + 2 Sqrt[5]]), 100]
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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